| 1 | # informix.py |
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| 2 | # Copyright (C) 2005,2006, 2007, 2008, 2009 Michael Bayer mike_mp@zzzcomputing.com |
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| 3 | # |
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| 4 | # coding: gbk |
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| 5 | # |
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| 6 | # This module is part of SQLAlchemy and is released under |
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| 7 | # the MIT License: http://www.opensource.org/licenses/mit-license.php |
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| 8 | |
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| 9 | import datetime |
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| 10 | |
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| 11 | from sqlalchemy import sql, schema, exc, pool, util |
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| 12 | from sqlalchemy.sql import compiler |
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| 13 | from sqlalchemy.engine import default |
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| 14 | from sqlalchemy import types as sqltypes |
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| 15 | |
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| 16 | |
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| 17 | # for offset |
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| 18 | |
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| 19 | class informix_cursor(object): |
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| 20 | def __init__( self , con ): |
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| 21 | self.__cursor = con.cursor() |
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| 22 | self.rowcount = 0 |
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| 23 | |
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| 24 | def offset( self , n ): |
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| 25 | if n > 0: |
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| 26 | self.fetchmany( n ) |
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| 27 | self.rowcount = self.__cursor.rowcount - n |
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| 28 | if self.rowcount < 0: |
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| 29 | self.rowcount = 0 |
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| 30 | else: |
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| 31 | self.rowcount = self.__cursor.rowcount |
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| 32 | |
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| 33 | def execute( self , sql , params ): |
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| 34 | if params is None or len( params ) == 0: |
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| 35 | params = [] |
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| 36 | |
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| 37 | return self.__cursor.execute( sql , params ) |
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| 38 | |
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| 39 | def __getattr__( self , name ): |
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| 40 | if name not in ( 'offset' , '__cursor' , 'rowcount' , '__del__' , 'execute' ): |
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| 41 | return getattr( self.__cursor , name ) |
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| 42 | |
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| 43 | class InfoNumeric(sqltypes.Numeric): |
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| 44 | def get_col_spec(self): |
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| 45 | if not self.precision: |
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| 46 | return 'NUMERIC' |
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| 47 | else: |
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| 48 | return "NUMERIC(%(precision)s, %(scale)s)" % {'precision': self.precision, 'scale' : self.scale} |
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| 49 | |
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| 50 | class InfoInteger(sqltypes.Integer): |
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| 51 | def get_col_spec(self): |
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| 52 | return "INTEGER" |
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| 53 | |
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| 54 | class InfoSmallInteger(sqltypes.Smallinteger): |
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| 55 | def get_col_spec(self): |
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| 56 | return "SMALLINT" |
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| 57 | |
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| 58 | class InfoDate(sqltypes.Date): |
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| 59 | def get_col_spec( self ): |
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| 60 | return "DATE" |
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| 61 | |
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| 62 | class InfoDateTime(sqltypes.DateTime ): |
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| 63 | def get_col_spec(self): |
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| 64 | return "DATETIME YEAR TO SECOND" |
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| 65 | |
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| 66 | def bind_processor(self, dialect): |
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| 67 | def process(value): |
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| 68 | if value is not None: |
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| 69 | if value.microsecond: |
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| 70 | value = value.replace( microsecond = 0 ) |
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| 71 | return value |
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| 72 | return process |
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| 73 | |
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| 74 | class InfoTime(sqltypes.Time ): |
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| 75 | def get_col_spec(self): |
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| 76 | return "DATETIME HOUR TO SECOND" |
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| 77 | |
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| 78 | def bind_processor(self, dialect): |
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| 79 | def process(value): |
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| 80 | if value is not None: |
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| 81 | if value.microsecond: |
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| 82 | value = value.replace( microsecond = 0 ) |
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| 83 | return value |
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| 84 | return process |
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| 85 | |
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| 86 | def result_processor(self, dialect): |
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| 87 | def process(value): |
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| 88 | if isinstance( value , datetime.datetime ): |
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| 89 | return value.time() |
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| 90 | else: |
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| 91 | return value |
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| 92 | return process |
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| 93 | |
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| 94 | class InfoText(sqltypes.String): |
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| 95 | def get_col_spec(self): |
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| 96 | return "VARCHAR(255)" |
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| 97 | |
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| 98 | class InfoString(sqltypes.String): |
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| 99 | def get_col_spec(self): |
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| 100 | return "VARCHAR(%(length)s)" % {'length' : self.length} |
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| 101 | |
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| 102 | def bind_processor(self, dialect): |
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| 103 | def process(value): |
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| 104 | if value == '': |
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| 105 | return None |
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| 106 | else: |
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| 107 | return value |
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| 108 | return process |
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| 109 | |
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| 110 | class InfoChar(sqltypes.CHAR): |
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| 111 | def get_col_spec(self): |
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| 112 | return "CHAR(%(length)s)" % {'length' : self.length} |
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| 113 | |
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| 114 | class InfoBinary(sqltypes.Binary): |
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| 115 | def get_col_spec(self): |
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| 116 | return "BYTE" |
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| 117 | |
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| 118 | class InfoBoolean(sqltypes.Boolean): |
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| 119 | default_type = 'NUM' |
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| 120 | def get_col_spec(self): |
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| 121 | return "SMALLINT" |
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| 122 | |
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| 123 | def result_processor(self, dialect): |
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| 124 | def process(value): |
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| 125 | if value is None: |
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| 126 | return None |
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| 127 | return value and True or False |
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| 128 | return process |
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| 129 | |
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| 130 | def bind_processor(self, dialect): |
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| 131 | def process(value): |
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| 132 | if value is True: |
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| 133 | return 1 |
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| 134 | elif value is False: |
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| 135 | return 0 |
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| 136 | elif value is None: |
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| 137 | return None |
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| 138 | else: |
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| 139 | return value and True or False |
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| 140 | return process |
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| 141 | |
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| 142 | colspecs = { |
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| 143 | sqltypes.Integer : InfoInteger, |
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| 144 | sqltypes.Smallinteger : InfoSmallInteger, |
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| 145 | sqltypes.Numeric : InfoNumeric, |
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| 146 | sqltypes.Float : InfoNumeric, |
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| 147 | sqltypes.DateTime : InfoDateTime, |
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| 148 | sqltypes.Date : InfoDate, |
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| 149 | sqltypes.Time: InfoTime, |
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| 150 | sqltypes.String : InfoString, |
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| 151 | sqltypes.Binary : InfoBinary, |
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| 152 | sqltypes.Boolean : InfoBoolean, |
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| 153 | sqltypes.Text : InfoText, |
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| 154 | sqltypes.CHAR: InfoChar, |
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| 155 | } |
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| 156 | |
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| 157 | |
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| 158 | ischema_names = { |
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| 159 | 0 : InfoString, # CHAR |
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| 160 | 1 : InfoSmallInteger, # SMALLINT |
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| 161 | 2 : InfoInteger, # INT |
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| 162 | 3 : InfoNumeric, # Float |
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| 163 | 3 : InfoNumeric, # SmallFloat |
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| 164 | 5 : InfoNumeric, # DECIMAL |
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| 165 | 6 : InfoInteger, # Serial |
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| 166 | 7 : InfoDate, # DATE |
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| 167 | 8 : InfoNumeric, # MONEY |
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| 168 | 10 : InfoDateTime, # DATETIME |
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| 169 | 11 : InfoBinary, # BYTE |
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| 170 | 12 : InfoText, # TEXT |
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| 171 | 13 : InfoString, # VARCHAR |
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| 172 | 15 : InfoString, # NCHAR |
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| 173 | 16 : InfoString, # NVARCHAR |
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| 174 | 17 : InfoInteger, # INT8 |
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| 175 | 18 : InfoInteger, # Serial8 |
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| 176 | 43 : InfoString, # LVARCHAR |
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| 177 | -1 : InfoBinary, # BLOB |
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| 178 | -1 : InfoText, # CLOB |
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| 179 | } |
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| 180 | |
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| 181 | |
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| 182 | class InfoExecutionContext(default.DefaultExecutionContext): |
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| 183 | # cursor.sqlerrd |
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| 184 | # 0 - estimated number of rows returned |
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| 185 | # 1 - serial value after insert or ISAM error code |
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| 186 | # 2 - number of rows processed |
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| 187 | # 3 - estimated cost |
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| 188 | # 4 - offset of the error into the SQL statement |
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| 189 | # 5 - rowid after insert |
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| 190 | def post_exec(self): |
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| 191 | if getattr(self.compiled, "isinsert", False) and self.last_inserted_ids() is None: |
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| 192 | self._last_inserted_ids = [self.cursor.sqlerrd[1]] |
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| 193 | elif hasattr( self.compiled , 'offset' ): |
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| 194 | self.cursor.offset( self.compiled.offset ) |
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| 195 | super(InfoExecutionContext, self).post_exec() |
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| 196 | |
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| 197 | def create_cursor( self ): |
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| 198 | return informix_cursor( self.connection.connection ) |
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| 199 | |
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| 200 | class InfoDialect(default.DefaultDialect): |
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| 201 | name = 'informix' |
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| 202 | default_paramstyle = 'qmark' |
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| 203 | # for informix 7.31 |
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| 204 | max_identifier_length = 18 |
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| 205 | |
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| 206 | def __init__(self, use_ansi=True, **kwargs): |
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| 207 | self.use_ansi = use_ansi |
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| 208 | default.DefaultDialect.__init__(self, **kwargs) |
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| 209 | |
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| 210 | def dbapi(cls): |
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| 211 | import informixdb |
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| 212 | return informixdb |
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| 213 | dbapi = classmethod(dbapi) |
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| 214 | |
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| 215 | def is_disconnect(self, e): |
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| 216 | if isinstance(e, self.dbapi.OperationalError): |
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| 217 | return 'closed the connection' in str(e) or 'connection not open' in str(e) |
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| 218 | else: |
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| 219 | return False |
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| 220 | |
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| 221 | def do_begin(self , connect ): |
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| 222 | cu = connect.cursor() |
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| 223 | cu.execute( 'SET LOCK MODE TO WAIT' ) |
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| 224 | #cu.execute( 'SET ISOLATION TO REPEATABLE READ' ) |
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| 225 | |
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| 226 | def type_descriptor(self, typeobj): |
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| 227 | return sqltypes.adapt_type(typeobj, colspecs) |
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| 228 | |
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| 229 | def create_connect_args(self, url): |
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| 230 | if url.host: |
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| 231 | dsn = '%s@%s' % ( url.database , url.host ) |
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| 232 | else: |
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| 233 | dsn = url.database |
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| 234 | |
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| 235 | if url.username: |
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| 236 | opt = { 'user':url.username , 'password': url.password } |
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| 237 | else: |
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| 238 | opt = {} |
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| 239 | |
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| 240 | return ([dsn], opt) |
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| 241 | |
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| 242 | def table_names(self, connection, schema): |
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| 243 | s = "select tabname from systables" |
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| 244 | return [row[0] for row in connection.execute(s)] |
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| 245 | |
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| 246 | def has_table(self, connection, table_name, schema=None): |
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| 247 | cursor = connection.execute("""select tabname from systables where tabname=?""", table_name.lower() ) |
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| 248 | return bool( cursor.fetchone() is not None ) |
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| 249 | |
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| 250 | def reflecttable(self, connection, table, include_columns): |
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| 251 | c = connection.execute ("select distinct OWNER from systables where tabname=?", table.name.lower() ) |
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| 252 | rows = c.fetchall() |
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| 253 | if not rows : |
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| 254 | raise exc.NoSuchTableError(table.name) |
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| 255 | else: |
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| 256 | if table.owner is not None: |
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| 257 | if table.owner.lower() in [r[0] for r in rows]: |
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| 258 | owner = table.owner.lower() |
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| 259 | else: |
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| 260 | raise AssertionError("Specified owner %s does not own table %s"%(table.owner, table.name)) |
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| 261 | else: |
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| 262 | if len(rows)==1: |
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| 263 | owner = rows[0][0] |
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| 264 | else: |
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| 265 | raise AssertionError("There are multiple tables with name %s in the schema, you must specifie owner"%table.name) |
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| 266 | |
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| 267 | c = connection.execute ("""select colname , coltype , collength , t3.default , t1.colno from syscolumns as t1 , systables as t2 , OUTER sysdefaults as t3 |
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| 268 | where t1.tabid = t2.tabid and t2.tabname=? and t2.owner=? |
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| 269 | and t3.tabid = t2.tabid and t3.colno = t1.colno |
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| 270 | order by t1.colno""", table.name.lower(), owner ) |
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| 271 | rows = c.fetchall() |
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| 272 | |
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| 273 | if not rows: |
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| 274 | raise exc.NoSuchTableError(table.name) |
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| 275 | |
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| 276 | for name , colattr , collength , default , colno in rows: |
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| 277 | name = name.lower() |
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| 278 | if include_columns and name not in include_columns: |
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| 279 | continue |
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| 280 | |
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| 281 | # in 7.31, coltype = 0x000 |
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| 282 | # ^^-- column type |
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| 283 | # ^-- 1 not null , 0 null |
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| 284 | nullable , coltype = divmod( colattr , 256 ) |
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| 285 | if coltype not in ( 0 , 13 ) and default: |
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| 286 | default = default.split()[-1] |
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| 287 | |
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| 288 | if coltype == 0 or coltype == 13: # char , varchar |
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| 289 | coltype = ischema_names.get(coltype, InfoString)(collength) |
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| 290 | if default: |
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| 291 | default = "'%s'" % default |
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| 292 | elif coltype == 5: # decimal |
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| 293 | precision , scale = ( collength & 0xFF00 ) >> 8 , collength & 0xFF |
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| 294 | if scale == 255: |
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| 295 | scale = 0 |
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| 296 | coltype = InfoNumeric(precision, scale) |
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| 297 | else: |
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| 298 | try: |
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| 299 | coltype = ischema_names[coltype] |
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| 300 | except KeyError: |
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| 301 | util.warn("Did not recognize type '%s' of column '%s'" % |
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| 302 | (coltype, name)) |
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| 303 | coltype = sqltypes.NULLTYPE |
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| 304 | |
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| 305 | colargs = [] |
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| 306 | if default is not None: |
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| 307 | colargs.append(schema.DefaultClause(sql.text(default))) |
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| 308 | |
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| 309 | table.append_column(schema.Column(name, coltype, nullable = (nullable == 0), *colargs)) |
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| 310 | |
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| 311 | # FK |
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| 312 | c = connection.execute("""select t1.constrname as cons_name , t1.constrtype as cons_type , |
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| 313 | t4.colname as local_column , t7.tabname as remote_table , |
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| 314 | t6.colname as remote_column |
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| 315 | from sysconstraints as t1 , systables as t2 , |
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| 316 | sysindexes as t3 , syscolumns as t4 , |
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| 317 | sysreferences as t5 , syscolumns as t6 , systables as t7 , |
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| 318 | sysconstraints as t8 , sysindexes as t9 |
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| 319 | where t1.tabid = t2.tabid and t2.tabname=? and t2.owner=? and t1.constrtype = 'R' |
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| 320 | and t3.tabid = t2.tabid and t3.idxname = t1.idxname |
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| 321 | and t4.tabid = t2.tabid and t4.colno = t3.part1 |
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| 322 | and t5.constrid = t1.constrid and t8.constrid = t5.primary |
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| 323 | and t6.tabid = t5.ptabid and t6.colno = t9.part1 and t9.idxname = t8.idxname |
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| 324 | and t7.tabid = t5.ptabid""", table.name.lower(), owner ) |
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| 325 | rows = c.fetchall() |
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| 326 | fks = {} |
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| 327 | for cons_name, cons_type, local_column, remote_table, remote_column in rows: |
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| 328 | try: |
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| 329 | fk = fks[cons_name] |
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| 330 | except KeyError: |
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| 331 | fk = ([], []) |
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| 332 | fks[cons_name] = fk |
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| 333 | refspec = ".".join([remote_table, remote_column]) |
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| 334 | schema.Table(remote_table, table.metadata, autoload=True, autoload_with=connection) |
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| 335 | if local_column not in fk[0]: |
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| 336 | fk[0].append(local_column) |
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| 337 | if refspec not in fk[1]: |
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| 338 | fk[1].append(refspec) |
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| 339 | |
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| 340 | for name, value in fks.iteritems(): |
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| 341 | table.append_constraint(schema.ForeignKeyConstraint(value[0], value[1] , None, link_to_name=True )) |
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| 342 | |
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| 343 | # PK |
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| 344 | c = connection.execute("""select t1.constrname as cons_name , t1.constrtype as cons_type , |
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| 345 | t4.colname as local_column |
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| 346 | from sysconstraints as t1 , systables as t2 , |
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| 347 | sysindexes as t3 , syscolumns as t4 |
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| 348 | where t1.tabid = t2.tabid and t2.tabname=? and t2.owner=? and t1.constrtype = 'P' |
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| 349 | and t3.tabid = t2.tabid and t3.idxname = t1.idxname |
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| 350 | and t4.tabid = t2.tabid and t4.colno = t3.part1""", table.name.lower(), owner ) |
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| 351 | rows = c.fetchall() |
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| 352 | for cons_name, cons_type, local_column in rows: |
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| 353 | table.primary_key.add( table.c[local_column] ) |
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| 354 | |
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| 355 | class InfoCompiler(compiler.DefaultCompiler): |
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| 356 | """Info compiler modifies the lexical structure of Select statements to work under |
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| 357 | non-ANSI configured Oracle databases, if the use_ansi flag is False.""" |
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| 358 | |
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| 359 | def __init__(self, *args, **kwargs): |
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| 360 | self.limit = 0 |
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| 361 | self.offset = 0 |
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| 362 | |
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| 363 | compiler.DefaultCompiler.__init__( self , *args, **kwargs ) |
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| 364 | |
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| 365 | def default_from(self): |
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| 366 | return " from systables where tabname = 'systables' " |
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| 367 | |
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| 368 | def get_select_precolumns( self , select ): |
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| 369 | s = select._distinct and "DISTINCT " or "" |
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| 370 | # only has limit |
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| 371 | if select._limit: |
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| 372 | off = select._offset or 0 |
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| 373 | s += " FIRST %s " % ( select._limit + off ) |
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| 374 | else: |
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| 375 | s += "" |
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| 376 | return s |
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| 377 | |
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| 378 | def visit_select(self, select): |
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| 379 | if select._offset: |
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| 380 | self.offset = select._offset |
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| 381 | self.limit = select._limit or 0 |
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| 382 | # the column in order by clause must in select too |
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| 383 | |
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| 384 | def __label( c ): |
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| 385 | try: |
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| 386 | return c._label.lower() |
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| 387 | except: |
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| 388 | return '' |
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| 389 | |
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| 390 | # TODO: dont modify the original select, generate a new one |
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| 391 | a = [ __label(c) for c in select._raw_columns ] |
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| 392 | for c in select._order_by_clause.clauses: |
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| 393 | if ( __label(c) not in a ): |
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| 394 | select.append_column( c ) |
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| 395 | |
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| 396 | return compiler.DefaultCompiler.visit_select(self, select) |
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| 397 | |
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| 398 | def limit_clause(self, select): |
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| 399 | return "" |
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| 400 | |
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| 401 | def visit_function( self , func ): |
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| 402 | if func.name.lower() == 'current_date': |
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| 403 | return "today" |
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| 404 | elif func.name.lower() == 'current_time': |
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| 405 | return "CURRENT HOUR TO SECOND" |
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| 406 | elif func.name.lower() in ( 'current_timestamp' , 'now' ): |
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| 407 | return "CURRENT YEAR TO SECOND" |
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| 408 | else: |
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| 409 | return compiler.DefaultCompiler.visit_function( self , func ) |
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| 410 | |
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| 411 | def visit_clauselist(self, list, **kwargs): |
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| 412 | return ', '.join([s for s in [self.process(c) for c in list.clauses] if s is not None]) |
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| 413 | |
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| 414 | class InfoSchemaGenerator(compiler.SchemaGenerator): |
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| 415 | def get_column_specification(self, column, first_pk=False): |
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| 416 | colspec = self.preparer.format_column(column) |
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| 417 | if column.primary_key and len(column.foreign_keys)==0 and column.autoincrement and \ |
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| 418 | isinstance(column.type, sqltypes.Integer) and not getattr( self , 'has_serial' , False ) and first_pk: |
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| 419 | colspec += " SERIAL" |
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| 420 | self.has_serial = True |
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| 421 | else: |
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| 422 | colspec += " " + column.type.dialect_impl(self.dialect).get_col_spec() |
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| 423 | default = self.get_column_default_string(column) |
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| 424 | if default is not None: |
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| 425 | colspec += " DEFAULT " + default |
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| 426 | |
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| 427 | if not column.nullable: |
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| 428 | colspec += " NOT NULL" |
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| 429 | |
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| 430 | return colspec |
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| 431 | |
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| 432 | def post_create_table(self, table): |
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| 433 | if hasattr( self , 'has_serial' ): |
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| 434 | del self.has_serial |
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| 435 | return '' |
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| 436 | |
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| 437 | def visit_primary_key_constraint(self, constraint): |
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| 438 | # for informix 7.31 not support constraint name |
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| 439 | name = constraint.name |
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| 440 | constraint.name = None |
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| 441 | super(InfoSchemaGenerator, self).visit_primary_key_constraint(constraint) |
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| 442 | constraint.name = name |
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| 443 | |
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| 444 | def visit_unique_constraint(self, constraint): |
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| 445 | # for informix 7.31 not support constraint name |
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| 446 | name = constraint.name |
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| 447 | constraint.name = None |
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| 448 | super(InfoSchemaGenerator, self).visit_unique_constraint(constraint) |
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| 449 | constraint.name = name |
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| 450 | |
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| 451 | def visit_foreign_key_constraint( self , constraint ): |
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| 452 | if constraint.name is not None: |
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| 453 | constraint.use_alter = True |
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| 454 | else: |
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| 455 | super( InfoSchemaGenerator , self ).visit_foreign_key_constraint( constraint ) |
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| 456 | |
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| 457 | def define_foreign_key(self, constraint): |
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| 458 | # for informix 7.31 not support constraint name |
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| 459 | if constraint.use_alter: |
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| 460 | name = constraint.name |
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| 461 | constraint.name = None |
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| 462 | self.append( "CONSTRAINT " ) |
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| 463 | super(InfoSchemaGenerator, self).define_foreign_key(constraint) |
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| 464 | constraint.name = name |
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| 465 | if name is not None: |
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| 466 | self.append( " CONSTRAINT " + name ) |
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| 467 | else: |
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| 468 | super(InfoSchemaGenerator, self).define_foreign_key(constraint) |
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| 469 | |
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| 470 | def visit_index(self, index): |
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| 471 | if len( index.columns ) == 1 and index.columns[0].foreign_key: |
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| 472 | return |
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| 473 | super(InfoSchemaGenerator, self).visit_index(index) |
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| 474 | |
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| 475 | class InfoIdentifierPreparer(compiler.IdentifierPreparer): |
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| 476 | def __init__(self, dialect): |
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| 477 | super(InfoIdentifierPreparer, self).__init__(dialect, initial_quote="'") |
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| 478 | |
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| 479 | def _requires_quotes(self, value): |
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| 480 | return False |
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| 481 | |
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| 482 | class InfoSchemaDropper(compiler.SchemaDropper): |
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| 483 | def drop_foreignkey(self, constraint): |
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| 484 | if constraint.name is not None: |
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| 485 | super( InfoSchemaDropper , self ).drop_foreignkey( constraint ) |
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| 486 | |
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| 487 | dialect = InfoDialect |
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| 488 | poolclass = pool.SingletonThreadPool |
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| 489 | dialect.statement_compiler = InfoCompiler |
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| 490 | dialect.schemagenerator = InfoSchemaGenerator |
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| 491 | dialect.schemadropper = InfoSchemaDropper |
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| 492 | dialect.preparer = InfoIdentifierPreparer |
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| 493 | dialect.execution_ctx_cls = InfoExecutionContext |
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